Hello, I have a question regarding the Sig P229 SAS in 9mm. Now I know there are conversion kits for the Sig, allowing it to be swapped from 9mm to 22LR. and like the .40, you can swap it into 9mm by changing the barrel and mag out. now is it possible to do it the opposite way? can i convert my 9mm into a .40 by getting the barrel and a mag? just a question out of curiosity.

Probably not as most .40s are designed to be a lot beefier than a 9mm. The breech face will be smaller on a 9mm than a .40 as well. You could probably use the frame and buy everything else, but you may as well just get another gun. Going down is generally OK but going up is very iffy...

i appreciate the info. and i have to agree, i was just curious to see if it has been done. but after you add a new barrel, slide, mag... and take the chance of destroying a great 9mm gun... its best to just buy a .40 if im that into it. thanks for the input!